Microsoft Lync CVE-2012-1849 DLL Loading Arbitrary Code Execution Vulnerability

Description

Microsoft Lync is prone to vulnerability that lets attackers execute arbitrary code. An attacker can exploit this issue by enticing a legitimate user to use the vulnerable application to open a file from a network share location which contains a specially crafted Dynamic Link Library (DLL) file. Successful exploits will compromise the application in the context of the currently logged-in user.

Technologies Affected

• Microsoft Lync 2010
• Microsoft Lync 2010 Attendant (32-bit)
• Microsoft Lync 2010 Attendant (64-bit)
• Microsoft Lync 2010 Attendee
• Microsoft Office Communicator 2007 R2

Recommendations

Block external access at the network boundary, unless external parties require service.
If global access isn’t needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of successful exploits.

Run all software as a nonprivileged user with minimal access rights.
To reduce the impact of latent vulnerabilities, always run nonadministrative software as an unprivileged user with minimal access rights.

Do not accept or execute files from untrusted or unknown sources.
Exercise caution when handling files received from unfamiliar or suspicious sources.

Do not follow links provided by unknown or untrusted sources.
Web users should be cautious about following links to sites that are provided by unfamiliar or suspicious sources. Filtering HTML from emails may help remove a possible vector for transmitting malicious links to users.

The vendor has released an advisory and updates. Please see the references for details.